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The subtraction imaging in confocal microscopy is demonstrated by using two vector beams with radial and azimuthal polarizations. The longitudinal electric component, which appears near the focus of a radially polarized beam under the tight focusing condition and produces a smaller focal spot, is effectively extracted by the subtraction using an azimuthally polarized beam. This subtraction imaging with vector beams provides the improvement of the lateral resolution in confocal microscopy without the degradation due to the excess subtraction.

We proposed a subtraction method using vector beams for resolution enhancement in confocal microscopy. The imaging simulation revealed that the negative side lobe due to the excess subtraction resulted in the degradation of the object image. The subtraction imaging using vector beams demonstrated high spatial resolution with avoiding the negative side lobe. Further resolution enhancement beyond 100 nm was predicted by using a flat-top beam obtained by the combination of beams with radial and azimuthal polarizations and a higher-order transverse mode azimuthally polarized beam without significant negative side lobe.